1. Field of the Invention
The present invention relates to a managing method of a run of movable objects such as a non-attendant transporting vehicle and the like, more specifically, it relates to a managing method of a run of movable objects in which the simulation result and a predetermined moving sequence are used together to select the movable objects and running routes in response thereto.
2. Description of Related Art
Recently, thanks to development of the so-called factory automation (FA), a non-attendant transporting vehicle which is a moving object running automatically without attendant is used for transporting material parts or half-finished parts in the factory, or further for storing and shipping materials and products in and out from the warehouse.
However, when managing a run of the non-attendant transporting vehicle as described above, a deadlock or standstill situation may arise between successive vehicles which disable the control and so creates a problem. In order to avoid this problem, restrictions are made to the layout and running of a wagon, or methods and programs are prepared for every individual case. For instance, it has been devised to restrict the running direction on the route to one way, or to restrict the routes between stations to one, and locally controlling at branches and junctions by a sensor such as an ultrasonic sensor, a photoelectric switch etc., or to leave sufficient space on the route so as not to influence the branches and junctions even when a succeeding vehicle is stopped due to operations of a preceding vehicle.
In a managing method of a run employing such restrictions, however, since two-way running on a single route is not possible, such problems as follows are encountered; the transportation efficiency deteriorate and space utilization efficiency, cost increases due to installation of sensors for local branch-junction control and the flexibility of layout decreases. It is also disadvantageous with respect to reliability, maintainability and cost since the programs cannot be standardized.
There is a method using an internal simulation as one of the methods for selecting and deciding a transporting vehicle and for flexibility running the route to standardize the programs, without restricting as much as possible the layout such as a single route running one-way. That is, a method for selecting the transporting vehicle and deciding the running route under a constant reference, by performing the internal simulation for every transporting vehicle including the running vehicle and every route, when the moving demand is generated.
According to the internal simulation, the moving demand may be realized within the shortest possible time. However, combinations are always a problem, the number of which becomes huge when all transporting vehicles and routes have to be simulated.
When a specific vehicle is directed to a specific station on a specific running route, and when the other vehicle is stopped on the running route or at station, the shunting is generated. When the shunting is generated, the simulation must be performed including movement for shunting of the impeding vehicle, which, in turn, may cause shunting of the other vehicle and so on in a chain reaction. If all combinations are simulated, it takes a lot of time to get an answer for one moving demand, which is impractical.
When managing a run by the simulation, the aforesaid deadlock disabling the simulation may occur.
As a managing method of a run without using the simulation, moving sequences including the operations of loading and unloading may be prepared in advance for every condition. For every demand for moving each of the vehicles including the running vehicle the managing method includes calling the one corresponding to the condition, and selecting the vehicle and deciding the running route including the movement of the other vehicle. According to this method, since the deadlock can be checked in advance, there is no possibility of the deadlock. However, the more in advance that the optimum vehicle and running route are to be decided, the more the condition must be classified precisely to circumstances, resulting in a large number of moving sequences as well as utilization of a greater capacity of memory. Further, it takes longer to set data for preparing the moving sequences, which is not practical.